Ground water input to coastal salt ponds of southern Rhode Island estimated using Ra-226 as a tracer

The naturally occurring radionuclide Ra-226 (t(1/2)=1600 years) was used as a tracer to determine ground water input to Point Judith, Potter, Green Hi ll and Ninigret ponds in southern Rhode Island. Measurements of 226Ra activ ity were made in samples collected from salt ponds, pore waters, sediments, and local ground water wells during June-August, 1997. These results were combined with a simple box model to derive ground water input fluxes of 0.1 -0.3 cm(3) cm(-2) d(-1) (2-5 X 10(7) L d(-1)), which are comparable to prev ious estimates of ground water input to these ponds. (C) 2001 Elsevier Scie nce Ltd. All rights reserved.